It is well known that scattered X-rays significantly degrade image contrast in mammography. As a result commercially available mammography units all employ low ratio grids to reduce the effects of scatter and image contrast. However, conventional mammography grids are limited in their ability to control scatter, particularly for thick dense breasts, and marked improvement in image contrast is possible with more efficient scatter control. Such improvements have been demonstrated with high ratio, high primary transmission grids. However, these grids have to move through a large distance to suppress grid artifacts, are bulky, and have limited patient positioning flexibility. Described as a practical and compact high ratio, high primary transmission mammography grid system. In Phase I the feasibility of such an approach was demonstrated. The goals in Phase II are to design and fabricate a high ratio, high primary transmission grid system; to evaluate its performance with phantoms; and to demonstrate its clinical utility. PROPOSED COMMERCIAL APPLICATIONS: The invention and technology described and being developed is directly applicable to clinical mammography. Two grid systems are used on every mammography unit. The technology being developed will be superior to conventional mammography grids and will be comparable in cost.